1. Field of the Invention
The present invention relates to a cartridge-type, compensating relief valve for use in a manifold cavity. In particular, the present invention relates to a cartridge-type, compensating relief valve for use in a manifold cavity having entry and exit fluid ports defining a fluid path, said valve comprising:
1) a gland removably secured with at least a portion thereof within at least a portion of said manifold cavity, said gland having a circular valve seat in operative communication with said fluid path of said manifold cavity, said gland having a central cavity therethrough; PA1 2) a valve stem extending through the central cavity of said gland and being moveable therein between an open valve position permitting fluid flow within said fluid path and a closed valve position prohibiting fluid flow within said fluid path, said valve stem further comprising: PA1 3) at least one internal fluid chamber in direct pressure communication with said entry port of said manifold cavity, and permitting fluid pressure approximately equal to the fluid pressure directed against the outward face of said piston to be directed against at least one internal surface of said valve stem, exerting a force tending to hold the valve in an open position; and, PA1 4) means to adjust the sensitivity of said valve. PA1 1) a gland removably secured with at least a portion thereof within at least a portion of said manifold cavity, said gland having a circular valve seat in operative communication with said fluid path of said manifold cavity, said gland having a central cavity therethrough; PA1 2) a valve stem extending through the central cavity of said gland and being moveable therein between an open valve position permitting fluid flow within said fluid path and a closed valve position prohibiting fluid flow within said fluid path, said valve stem further comprising: PA1 3) a first internal fluid chamber in direct pressure communication with said entry port of said manifold cavity by way of said piston ports, and permitting fluid pressure to be directed against the inward face of said piston, exerting a force upon said inward face tending to hold the valve in an open position; PA1 4) a second internal fluid chamber in direct pressure communication with said entry port of said manifold cavity by way of said central fluid communication port, and permitting fluid pressure to be directed against at least one internal surface of said valve stem, exerting a force upon said internal surface tending to hold the valve in an open position; and, PA1 5) means to adjust the sensitivity of said valve. PA1 1) a gland removably secured with at least a portion thereof within at least a portion of said manifold cavity, said gland having a circular valve seat in operative communication with said fluid path of said manifold cavity, said gland having a central cavity therethrough; PA1 2) a valve stem extending through the central cavity of said gland and being moveable therein between an open valve position permitting fluid flow within said fluid path and a closed valve position prohibiting fluid flow within said fluid path, said valve stem further comprising: PA1 3) at least one internal fluid chamber in direct pressure communication with said entry port of said manifold cavity, and permitting fluid pressure approximately equal to the fluid pressure directed against the outward face of said piston to be directed against at least one internal surface of said valve stem, exerting a force tending to hold the valve in an open position; and, PA1 4) means to adjust the sensitivity of said valve. PA1 1) a gland removably secured with at least a portion thereof within at least a portion of said manifold cavity, said gland having a circular valve seat in operative communication with said fluid path of said manifold cavity, said gland having a central cavity therethrough; PA1 2) a valve stem extending through the central cavity of said gland and being moveable therein between an open valve position permitting fluid flow within said fluid path and a closed valve position prohibiting fluid flow within said fluid path, said valve stem further comprising: PA1 3) a first internal fluid chamber in direct pressure communication with said entry port of said manifold cavity by way of said piston ports, and permitting fluid pressure to be directed against the inward face of said piston, exerting a force upon said inward face tending to hold the valve in an open position; PA1 4) a second internal fluid chamber in direct pressure communication with said entry port of said manifold cavity by way of said central fluid communication port, and permitting fluid pressure to be directed against at least one internal surface of said valve stem, exerting a force upon said internal surface tending to hold the valve in an open position; and, PA1 5) means to adjust the sensitivity of said valve.
a) a piston portion located at a first end of said valve stem extending into said manifold cavity and positioned within the fluid path of said manifold cavity, said piston portion having: PA2 b) a plurality of piston ports open in both the outward face and the inward face of said piston, said piston ports being radially divergent from a central point on the outward face of said piston to points around the circumference of the inward face of the piston in the area of said valve seat; PA2 a) a piston portion located at a first end of said valve stem extending into said manifold cavity and positioned within the fluid path of said manifold cavity, said piston portion having: PA2 b) a plurality of piston ports open in both the outward face and the inward face of said piston, said piston ports being radially divergent from a central point on the outward face of said piston to points around the circumference of the inward face of the piston in the area of said valve seat; and, PA2 c) a central fluid communication port in the outward face of said piston and extending centrally along at least a portion of the length of said valve stem; PA2 a) a piston portion located at a first end of said valve stem extending into said manifold cavity and positioned within the fluid path of said manifold cavity, said piston portion having: PA2 b) a plurality of piston ports open in both the outward face and the inward face of said piston, said piston ports being radially divergent from a central point on the outward face of said piston to points around the circumference of the inward face of the piston in the area of said valve seat; PA2 a) a piston portion located at a first end of said valve stem extending into said manifold cavity and positioned within the fluid path of said manifold cavity, said piston portion having: PA2 b) a plurality of piston ports open in both the outward face and the inward face of said piston, said piston ports being radially divergent from a central point on the outward face of said piston to points around the circumference of the inward face of the piston in the area of said valve seat; and, PA2 c) a central fluid communication port in the outward face of said piston and extending centrally along at least a portion of the length of said valve stem;
i) an outward face in direct fluid communication with said entry fluid port of said manifold cavity, such that fluid pressure on the surface area of said outward face of said piston tends to hold said valve in a closed position, and PA3 ii) an inward face in operative contact with the valve seat of said gland when said valve is in the closed position and in direct fluid communication with said exit port of said manifold cavity when said valve is in an open position; and, PA3 i) an outward face in direct fluid communication with said entry fluid port of said manifold cavity, such that fluid pressure on the surface area of said outward face of said piston tends to hold said valve in a closed position, and PA3 ii) an inward face in operative contact with the valve seat of said gland when said valve is in the closed position and in direct fluid communication with said exit port of said manifold cavity when said valve is in an open position; PA3 i) an outward face in direct fluid communication with said entry fluid port of said manifold cavity, such that fluid pressure on the surface area of said outward face of said piston tends to hold said valve in a closed position, and PA3 ii) an inward face in operative contact with the valve seat of said gland when said valve is in the closed position and in direct fluid communication with said exit port of said manifold cavity when said valve is in an open position; and, PA3 i) an outward face in direct fluid communication with said entry fluid port of said manifold cavity, such that fluid pressure on the surface area of said outward face of said piston tends to hold said valve in a closed position, and PA3 ii) an inward face in operative contact with the valve seat of said gland when said valve is in the closed position and in direct fluid communication with said exit port of said manifold cavity when said valve is in an open position;
According to another embodiment of the present invention, there is provided a cartridge-type, compensating relief valve for use in a manifold cavity having entry and exit fluid ports defining a fluid path, said valve comprising:
2. Description of Related Art
Cartridge within-a-cavity valves are widely used for controlling the flow of many fluids, including applications where the flow control of high pressure hydraulic fluid is desired. Cartridge-type valves are widely used because the internal components of the valve may be easily removed and replaced from a manifold cavity for maintenance and repair.
Cartridge valves are commonly used in a manifold cavity of the type shown in FIG. 1. Referring to this figure, fluid enters the cavity through port 6 and exhausts through port 5. A cylinder 4 receives the valve at the base of the manifold. Our earlier U.S. Pat. No. 5,255,704, shows an hydraulic valve intended for use in this environment, and the teachings of that reference are herein incorporated by reference as if fully set out herein.
That invention was successful in overcoming problems encountered in valves, but only for hydraulic valves, which could be opened or closed at an operators discretion, but which did not provide for automatic operation, as a check valve or relief valve might. Check valve are employed to be sure that fluid flow within a cavity can only be in one direction. A good example of such a valve appears in our earlier U.S. Pat. No. 4,936,339, entitled CARTRIDGE-TYPE CHECK VALVE. A relief valve, on the other hand, is intended to remain closed unless the pressure within a system exceeds a certain pre-selected limit, at which time the valve will automatically open, relieving the excess pressure.
One of the major difficulties with such relief valves, is that they require some kind of internal biasing, usually a strong spring, to provide the force necessary to keep the valve in a closed position. As the pressures for which the valves are employed increase, however, the spring tension coefficient k must increase as well, resulting in a need for a variety of valves for different pressure uses and a loss in sensitivity of the valve mechanism as the pressure requirements increase.